AMSTERDAM, Feb 10 (Reuters) - Flow Traders NV, a proprietary Dutch trading firm best known for market making in exchange-traded products (ETPs), on Thursday reported 2021 net trading income of 384 million euros ($439 million), in line with expectations, and said it was becoming a significant player in European crypto ETPs.

Analysts had seen full year trading income at 385 million euros, versus 933 million in 2020, according to Refinitiv data.

Flow Traders benefits from volatile markets and had windfall profits during the onset of the COVID-19 pandemic in March 2020.

The company also engages in off-exchange trading with institutional investors.

It has begun making markets in cryptocurrency ETPs, which have been listed on Switzerland's SIX exchange and Deutsche Boerse's Xetra, among others, and said on Thursday it now had a 45% market share among 125 crypto ETP listings in the Europe, Middle, East and Africa (EMEA) region.

Flow competes with privately-held Optiver, also of Amsterdam, and larger players such as U.S. firm Virtu Financial.

The company said it would increase fixed operating expenses by up to 15% in 2022 as it seeks to broaden its areas of expertise, targeting fixed income markets and single bond market making, in addition to crypto and digital assets.

Its shares are up 4.2% so far in 2022, closing on Wednesday at 33.56 euros apiece.

($1 = 0.8755 euros) (Reporting by Toby Sterling Editing by Mark Potter)